Subsequent Event Subsequent Event (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Sep. 29, 2017	Sep. 30, 2016
Subsequent Event [Line Items]
Acquisitions of businesses, equity method investments and nonmarketable securities		$ 538	$ 767
CCBA [Member]
Subsequent Event [Line Items]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	54.50%
Acquisitions of businesses, equity method investments and nonmarketable securities	$ 3,150